95 billion litres of freshwater are made from seawater each day. Why?

There are 1.4 billion cubic kilometers of water on the planet [1]. Yet, 40% of people face a severe lack of water, and this is predicted to increase to 60% by 2025 [2]. Animals such as sea otters can drink seawater because their kidneys have evolved to get rid of extra salt [3]. Humans, on the other hand, can’t cope with the salt in seawater [4]. If you drank seawater, to get rid of excess salt you would have to pee out more water than you drink, making you even thirstier [4]!

Us humans, being the creative animals we are, have come up with ways of taking salt out of seawater to make it drinkable [5]. In fact, the Maldives, Malta, and the Bahamas have made use of being surrounded by the ocean, and get all their water by converting seawater into fresh water (which contains much less salt [6]) [7]. This process is called “desalination” – about 6 teaspoons of salt need to be removed from each liter of water [8]!

About 95 million cubic meters of freshwater are produced by this process every day [9]. About half of this is in the Middle East and North Africa [9], where water shortage is common [10]. Check out our next posts for the pros and cons of desalination!